Hi stall converters without a trans brake. How to launch?

[2JZR31]

How are people getting good stall speeds off the line without lighting the wheels up or pushing the front when getting on the converter? Is anyone upgrading the rear brakes and handbrake etc? Will stalling in second gear do damage to the trans?

With the handbrake and brakes hard on I can only get 2500rpm in first with like 2 psi, and with the handbrake and brakes on in second I can get 3300rpm with about 8 psi.

[IN 05 NT]

you can get LINE LOCKERS, run them in you brake line,

http://cgi.ebay.com.au/B-M-LAUNCH-CO...QQcmdZViewItem

similar effect of using the handbrake idea, but use a switch/solenoid instead!

[2JZR31]

I have seen that, but I can't see how it will help with anything other than reducing rear brake pad ware.

[BeRad]

im no expert on auto's but if the stall is high then it shouldnt be locking up at 2400? therefore there shouldnt be full drive running into the diff so shoudlnt be spinning the wheels?

maybe the stall is not as high as you thought? just an idea.

[oldcorollas]

I have seen that, but I can't see how it will help with anything other than reducing rear brake pad ware.

no no... there are two line lockers..

one stops any pressure getting to the back brakes, so then you can do fully sik one leggers with your gemini or VL...

the other one, keeps pressure to the back brakes... you you apply brakes fully, then press line lock button, so the back brakes are kept on HARD.
then you can stall up, and when you launch, you release the fluid pressure from the rear brakes....

aiui

[2JZR31]

All hi stall converters will stall higher when you prevent the wheels from spinning and apply more torque from the engine. So the more torque the engine makes, and the more clamping force you have to prevent wheel spin, the higher you will be able to stall to. I have shown my converter can go to 3300rpm by stalling it in second gear (which reduces torque to the wheels to slow the onset of wheel spin)

[2JZR31]

no no... there are two line lockers..

one stops any pressure getting to the back brakes, so then you can do fully sik one leggers with your gemini or VL...

the other one, keeps pressure to the back brakes... you you apply brakes fully, then press line lock button, so the back brakes are kept on HARD.
then you can stall up, and when you launch, you release the fluid pressure from the rear brakes....

aiui

I appreciate that, but why is this going to be better than just holding my foot on the brake? I don't need a device to help me with this do I? Its not like it can magnify the clamping force to the rear brakes can it?

[BeRad]

so your holding your foot as hard as u can on the brake and its still spinning? i think hes was getting at that maybe you wernt holding your foot fully on the brake, if so you have to much torque

[2JZR31]

Of course I am holding it as hard as I can, and with the handbrake on as hard as it will go To much torque and not enough brake power I think.

[BeRad]

transbrake time.

[1JZ-Rolla]

I found the same issue with my 1JZ & 2800 stall at the toynats drags yesterday.... Couldn't get past a few psi & 2300-2400rpm before the rear tyres let go. What tyres do you have?

Unfortunately the A340 toyota auto is not able to be modified for a transbrake as far as I am aware

[EldarO]

had this problem with my p00 7M+Auto.

it was completely stock and i couldnt really get any kind of boost off the line with just the brakes before it started spinning, the only other option i had at the time was use the handbrake... got an extra 1000RPM and a few pounds of boost...

sadly theres not much more you can do.

Elmo.

[oldcorollas]

I appreciate that, but why is this going to be better than just holding my foot on the brake? I don't need a device to help me with this do I? Its not like it can magnify the clamping force to the rear brakes can it?

well.. you can't make the force bigger, but it might make for more consistent launches (for gumbys?).. since you only need to hit a switch to release the brakes and launch, as opposed to releasing your foot pressure and then lifting your leg....
only fractions of a second, but it might be of help.

you could also consider fitting larger diameter rear discs, and even a seperate brake pedal which only operates a second caliper on the rear (with big pistons).. kinda like how mercs have a seperate hand(foot)brake pedal.... then you can maximise the braking force to the rear (discs don't need to be very thick.. they just need the diameter.....) and combine with the line locker, so you don't need to fiddle with the two pedals when launching

that is if you can't fit a transbrake....

[Bored?]

Ok, this might be a stupid comment, because I know nothing about the transmission in question. I am assuming that it is an electronically controlled auto...

In that case, might it not be possible to wire up the electronic solenoids to select 1st and reverse simultaneously? (ie. implement the transbrake electronically).

[EldarO]

id imagine that would be a well smart way of killing your transmission quickly.

Elmo.